Rod bending machine



Jul 13, 1937. K PALMER 2,086,736

ROD BENDING MACHINE Filed Jan. 51, 1956 2 Sheets-Sheet 2.

lumen-but R.K.PHL[I1E.R

Eltlr-urneg Patented July 13, 1937 PATENT @FFECE BOD EEENDING MACHIINERobert Kendrick Palmer, Hamilton, Untario, Canada Application January31, 1936, Serial No. 61,701

15 Claims.

My invention relates to improvements in rod bending machines, and theobject of the invention is to devise means for simultaneously effectinga plurality of bends in a straight rod.

A further object is to devise means for facilitating the starting of thebending operation.

A still further object is to construct a machine which, by the changingof the elements of the bending mechanism, will produce a bent rod inwhich the bends are differently disposed and may be either uniform orvariable.

My machine is particularly applicable for form ing from straight rods Zor zig-zag skeleton webs for structural shapes or for formingreinforcing rods for concrete constructions, it being understood thatthe web so formed has all its bends disposed in the same plane.

With the above and other objects in View which will hereinafter appearas the specification proceeds, my invention consists, in its preferredembodiment, of the construction and arrangement all as hereinafter moreparticularly described and illustrated in the accompanying drawings inwhich:

Fig. 1 represents a plan View, shortened intermediately, of my machine.

Fig. 2 is a side elevational view thereof.

Fig. 3 is an enlarged vertical cross-sectional view taken on the line3-3 (Fig. 1).

Fig. 4 is an enlarged vertical sectional View of the driving gears of mymachine taken on the line 3-4 (Fig. 1).

Fig. 5 is a. fragmentary View similar to Fig. 1 showing an alternativearrangement of bending elements for a bent rod in which the bends taperin height from one end to the other, and

Fig. 6 is a fragmentary view similar to Fig. 1 showing the elements ofthe machine in the position they assume when the rod is completely bent.

Like characters of reference indicate corresponding parts in thedifferent views.

My machine comprises a bed 5 preferably supported on a concrete base 2,a bracket 3 on the bed having a plate t secured thereto. Opposed guides5, 5 extend longitudinally and centrally of the bed i in which a drivingblock 6 is adapted to slide, such driving block being secured to one endof a longitudinal screw l. The screw '1 is carried in a correspondinglythreaded gear 8 journalled in a split housing 83 secured to the plate 4.The gear 8 meshes with a worm it on a shaft I! also journalled in thehousing 9 and which may be driven by any suitable power means. Thehousing 9 is adapted to be filled with heavy oil (fill. 153-213) orgrease and sealing rings l2 therefor may be disposed on the shaft llbetween each end of the worm ii! and the adjacent face of the housing 9.The threading of the screw l is preferably of the square type.

A stationary block it is secured in the guides 5 at the end of the bed lremote from the housing t, and a plurality of blocks H are adapted toslide in the guides 5 between the blocks 6 and it. Each sliding blockill has a vertically disposed hollow fulcrum bearing l8 secured thereinon which crossed links it and 28 of a lazy tongs mechanism are pivotedintermediately of their length. Each link it is interposed between thelinks as which are double and the free ends of the double links arepivoted to the corresponding free ends of the single links. The endlinks 2| of the lazy tongs mechanism are half links and are pivoted onfulcrum pins 22, 22 secured in theblocks ii and i6 respectively.

A pin it is rotatably secured in the bore of each fulcrum bearing l8,and has an enlarged head 2 projecting above the bearing in which is anotch 25 to receive the rod 26 to be bent. The heads 2 of the pins arereceived in central vertical orifices ill in rod clamps 28 which areprovided with longitudinal rod-receiving grooves 29 of the samecross-section as the notches 25 in the pin heads, which grooves andnotches are adapted to register with each other, the clamps beingsecured against rotation on the pins by, for example, keys Sil, andagainst vertical displacement therefrom by set-screws 3|.

Links 32 are pivoted intermediately of their length on the fulcrumbearings i8 above the bars l9 and 2t and their free ends are pivotedtogether on pins 33, the end links 34 of such link system being halflinks pivoting on the fulcrum pins 22 in the blocks 6 and I6. The links32 and 3-5 are of such length that adjacent links are always disposed atan angle to each other even when the lazy tongs mechanism is extended tothe limits of its travel. A bend starting hook 35 is secured to each ofthe pins 33 to overlie the bars 32, one end of which is adapted tounderlie the bar 26 to be bent when the latter is positioned in theclamps 23 and has a rod engaging upstanding projection 36 thereon, andthe other end of which is provided with a longitudinal slot 31 in whichone of the pivot pins 38 for the levers l9 and 2G is adapted to slide.

A longitudinal notch 39 is also provided in the lower face of each clamp28 which is adapted to receive a cable to running longitudinally of themachine through orifices 41 in the head 24 of each pin 23 and anchoredat each end in thecorresponding pin head, which serves to align theclamps 28 when the lazy tongs mechanism is extended.

The operation of the device is as follows: By rotating the shaft H inthe proper direction the worm iii thereon causes the gear 8 to rotate,and since such gear is held against axial displacement in the housing 9the screw 1' draws the driving block in the guides 5 away from the fixedblock it which results in the lazy tongs mechanism being opened up untilthe cable ii] has rotated the clamps 22 into such position that all therod receiving grooves 29 therein are in alignment. lazy tongs mechanismthe links 32 and 34 move the starting hooks 35 toward the longitudinalcentre line of the lazy tongs. The rod 26 to be bent is then insertedinto the grooves 39 and the shaft ll is'rotated in the oppositedirection to cause the screw 'l'to move the driving block 6 towards thefixed block it. When this occurs, the closing up of the link system 32,34 causes the starting hooks 35 to move away from the longitudinalcentre line of the lazy tongs and the projections 3t engage the rod 25and start the bending operation which is then continued by the closingup of the lazy tongs mechanism. It will be observed that, due to theirangular relationship, the links 32, 34 carrying the starting hooks swingfaster than the links l9, 2a of the lazy tongs mechanism, but slowerthan the rod bends once the bends are started and since the startinghooks are disposed alternately on opposite sides of the lazy tongsmechanism a rod bent alternately one way and then the other isfabricated. It will also be evident that the moving relationship betweenthe starting hooks, the rod clamps and the rods is always such thatthere is complete clearance between these parts.

It will be obvious'from the above description and the drawings that byaltering the length of the links 69 and 20 and the length of the rodclamps 28 the rod instead of being bent to have uniform bends throughits length may be so bent that these bends taper from one end to theother (Fig. 5), from each end towards the centre, or in any otherdesired arrangement.

An advantage of my improved machine is that a large number of bends maybe made in a rod therewith simultaneously, so that the machinewill havea very high output of bent rods.

Yet another advantage is that, by providing a number or" interchangeablerod clamps, lazytong links and bend starting links of differentdimensions for the machine, a number of different types of bent rodshaving different arrangements of the bends may be produced in the onemachine.

A further advantage is that the position of each bend in a rod bent inmy machine is always exactly located by the rod clamps, so that all bentrods produced in the machine with one set of clamps are exact duplicatesof each other and the bends of each rod lie wholly in one plane. Inaddition, substantially the whole length .of each part of a rod betweenbends is supported by a rod clamp during bending of a rod, resulting insuch parts being straight in the finished bent rod. 7

What I claim as my invention is:

1. A rod bending machine comprising a plurality of rotatable rodengaging elements, means for slidably positioning the rod engaging ele-During such movement of the ments in alignment and in spaced relation toreceive a rod to be bent, means for engaging the rod between each pairof rotatable rod engaging elements for effecting initial bending of therod, and means for simultaneously decreasing I the spacing between therotatable rod engaging elements in the means for slidably positioningthe latter to complete the bending of the rod.

2. A rod bending machine comprising a lazy tongs, means for opening'andclosing the lazy tongs, rotatable rod engaging elements positioned atthe central intersections of the bars of the lazy tongs, means foraligning the rod engaging elements during opening of the lazy tongs toreceive a rod to be bent and means coacting with the lazy tongs forengaging the rod between each pair of rotatable rod engaging elementsand adapted to effect initial bending of the rod, the closing of thelazy tongs serving to complete the bending of the rod.

3. A rod bending machine as claimed in claim 2 wherein the means foropening and closing the lazy tongs comprises means in the machine forpositioning one end of the lazy tongs, a screw secured to the other endof the lazy tongs, a rotatable element threaded on said screw andsecured against axial displacement in the machine, and means forrotating the rotatable element. 7

i. A rod bending machine as claimed in claim 2 wherein the rod aligningmeans comprises a flexible member interconnecting said rotatable rodengaging elements.

5. A rod bending machine as claimed in claim 2 wherein the meanscoacting with the lazy tongs for engaging the rod comprises a plurality.of levers each pivoted on the lazy tongs at a central intersection of apair of bars thereof, a pin pivotally connecting one end of each leverto one end of the adjacent lever and a rod engaging member carried oneach pin, the length of the levers being such that the rod engagingmembers are disposed alternately on opposite sides of the longitudinalcentre line of the lazy tongs when the latter is open.

6. A rod bending machine comprising a bed, a guideway thereon, aplurality of blocks slidably secured in the guideway, a fulcrum on eachblock, a pair of cross-ed bars pivoted intermediately of their ends oneach fulcrum and pivotally connected together to form a lazy tongs,means for opening and closing the lazy'tongs, a rod clamp rotatablypositioned on each fulcrum, means for aligning the rod clamps duringopening of the lazy tongs to receive a rod to be bent, a plurality oflevers pivoted intermediately of their ends one on each fulcrum, a pinpivotally connecting one end of each lever to one end of the adjacentlever, and a bend starting hook carried on each pin, said levers beingof such length that the bend starting hooks are disposed alternately onopposite sides of thelongitudinal centre line of the lazy tongs when thelatter is open.

7. A rod bending machine as claimed in claim 6 wherein the means foropening and closing the lazy tongs comprises a member secured in theguideway to which one end of the lazy tongs is pivotally secured, amember slidable in the guideway to which the other end of the lazy tongsis pivotally secured, and means for moving the member slidably in theguideway away from and toward the member secured in the guideway.

8. A rod bending machine as claimed in claim 6 wherein the means foropening and closing the lazy tongs comprises a member secured in theguideway to which .one end of the lazy tongs is pivotally secured, amember slidable in the guideway to which the other end of the lazy tongsis pivotally secured, a threaded rod secured to the member slidable inthe guideway, a rotatable member thread-ed on the rod, means on the bedfor rotatably supporting the rotatable member against axial displacementin the machine, and means for rotating the rotatable member.

9. A rod bending machine as claimed in claim 6 wherein each rod clampcomprises a block having a rod receiving groove therein.

10. A rod bending machine as claimed in claim 6 wherein each rod clampcomprises a block having a rod receiving groove therein and the rodclamp aligning means comprises a flexible member secured at one end tothe fulcrum adjacent one end of the lazy tongs and at the other end tothe fulcrum adjacent the other end of the lazy tongs and means on eachrod clamp for engaging the flexible member.

11. A rod bending machine as claimed in claim 6 wherein each bendstarting hook comprises a plate, a hooked projection thereon adapted tounderlie and engage the rod to be bent, and means on the plate andengaging the lazy tongs for maintaining the hook at right angles to theaxis of extension of the lazy-tongs during open ing and closing of thelazy tongs.

12. A red bending machine comprising a bed, a gui'deway thereon, aplurality of blocks slidable in the guideway, a hollow fulcrum bearingprojecting from each block, a pair of levers journall-ed on each fulcrumbearing in X formation, a pin connecting one free extremity of eachlever to the opposite extremity of the adjacent lever, a fixed block inone end of the guideway, a pin secured in the block, a pair of linkspivotally connecting the pin with the free extremities of the adjacentpair of crossed levers, a driving block slidable in the other end of theguideway, a pin secured in the driving block, a pair of links pivotallyconnecting the pin with the free extremities of the adjacent pair ofcrossed levers, a threaded rod secured to the driving block, a worm gearthreaded on the rod, a housing secured to the bed and in which the gearis journalled against radial displacement, a worm journalled in thehousing and meshing with the gear, a pin rotatably secured in eachfulcrum bearing, a rod clamp mounted on each pin, means for aligning therod clamps to receive a rod to be bent during outward movement of thedriving block in the guideway, a bend starting bar journalledintermediately of its ends on each fulcrum bearing, a pin pivotallyconnecting one extremity of each bend starting bar to one extremity ofthe adjacent bar, a link pivotally connecting the pin in the fixed blockto the free end of the adjacent bend starting bar, a link pivotallyconnecting the pin in the driving block to the free end of the adjacentstarting bar, the lengths of the bend starting bars being such that eachis disposed at an angle to its neighbour when the driving block ispositioned at the outer limit of its movement in the guideway, and abend starting hook pivoted on each pivot pin of the bend starting barsadapted to engage the rod to be bent at a point between each adjacentpair of rod clamps, the bend starting hooks being directed alternatelytowards opposite sides of the guideway.

13. In a rod bending machine as claimed in claim 12, a head on the pinrotatably secured in each fulcrum bearing and having a rod receivingtransverse groove therein, a rod clamp comprising a block having a pinhead receiving orifice therein and a rod receiving groove adapted toregister with the groove in the pin head, and means for preventingrelative rotation of the pin head and the clamp.

14. A rod bending machine as claimed in claim 12 wherein the means foraligning the rod clamps comprises a cable secured at one end to the pinrotatably secured in the flucrum bearing adjacent the fixed block and atthe other end to the pin rotatably secured in the flucrum bearingadjacent the driving block and passing through orifices in theintervening pins and through grooves in the rod clamps registering withsuch orifices.

15. A rod bending machine as {claimed [in claim 12 wherein each bendstarting hook comprises a plate having an orifice for receiving one ofthe said pins pivotally connecting a pair of starting bars and having aslot therein adapted to slidably receive the pin on which the adjacentlevers of the first mentioned lever system are pivoted.

ROBERT KENDRICK PALMER.

